"With the stock down 15% in aftermarket trading, short sellers have made almost half a billion dollars on the stock price drop to $83.30," Ihor Dusaniwsky of S3 Partners, a financial analytics firm, told Business Insider in an email.

Hedge funds have been some of the most apt short sellers in the stock, according to a Goldman Sachs report from earlier this year.

When an investor is a "short seller," it means they are betting the stock price will go down.

There are also likely some hedge funders hurting on the Netflix news, however, as several managers held long positions in the stock. Tiger Global held a 4% stake while Viking Global held nearly a 2% stake in Netflix as of end of March, regulatory filings show. It's unclear if those funds still held their positions coming into Netflix's announcement.